Conditions for the emergence of life on earth. Living conditions on earth. Life forms of plants

It is difficult to say exactly how many hundreds of millions of years ago conditions for the emergence of life on Earth- appeared moisture defined stable temperatures and primary carbon compounds, which served as the basis for the creation protein bodies with a new property - self-exchange.

Evolution of matter on Earth

It is quite obvious that the emergence of such a remarkable property of matter, which transformed our planet, was preceded by a very long period evolution this matter on earth.

If we want to understand how our life came about, we must trace the history of the development of matter.

Academician A.I. Oparin Evolution of matter on Earth.

Development of matter from non-living matter to living matter

As you know, modern life can develop and exist within fairly narrow temperature limits. Polar algae are known red snow capable of growing even at minus 30 degrees, and hot spring algae existing at plus 70-90 degrees. These temperatures should be considered as possible temperature limits of the conditions in which life could arise. As the earth's crust cooled down on our planet, various chemical compounds... Synthetic chemistry is helping to figure out the conditions necessary for the emergence of life on Earth. The advances in chemistry fully support the proposed move development of matter from non-living matter to living... For example, the famous Russian chemist A.M.Butlerov in 1861, combining formalin (a poisonous substance that includes carbon, hydrogen, oxygen) with an aqueous solution of lime, obtained a sugar substance. Later, fats were also artificially obtained. And Academician A. N. Bach was the first to synthesize substances close to the simplest proteins.

Hypotheses about the origin of life on Earth

In the 19th century, there were several hypotheses about the origin of life on Earth. Some of them had the appearance of being scientific and were supposedly based on the achievements of physics and chemistry.

Hypotheses were widely spread according to which life on Earth developed from negligible embryos transferred to Earth from world space. The carriers of life were allegedly meteorites, that is, celestial bodies falling to the Earth.
Later, when the famous Russian physicist Lebedev proved the existence of light pressure, a hypothesis arose about the possibility of transferring the embryos of life from planet to planet by rays of light.

But these hypotheses actually did not explain anything, since it remained unresolved main question: How did life originate somewhere from where it was supposedly transferred to our Earth? In the nineteenth century, a hypothesis was put forward on the origin of life on the basis of an understanding of the general laws of the development of nature.

Life was not brought to us from somewhere from the world space, but arose here, on Earth, as a new stage in the development of matter. Matter in the conditions of a cooling planet gave more and more complex chemical compounds. As a result of the prolonged development of matter, its highest form arose - a protein substance with a new property of self-renewal. So to explain how life came about is to explain how the protein came about.

The theory of the origin of protein bodies

The most famous theory of the origin of protein bodies developed by a scientist academician A. I. Oparin... For many years he was engaged in the study of questions about the processes taking place on Earth, as a result of which life arose from inanimate matter. Oparin draws Special attention on the conditions that contributed to the emergence of living matter, and from it - living organisms. gradually cooled down, but the internal heat of the planet, (more:), was noticeably manifested for a long time: the water of the oceans was heated not only by the Sun, but also warmed up from below.

Ocean water. At that time the Earth had an unattractive appearance, (more:). In the vast, but still shallow ocean, in places stone cliffs protruded as sharp protrusions. There were still few sedimentary rocks, and the first continents had an angular, uneven relief. The atmosphere had a completely different composition than now. There was almost no gaseous oxygen in it (it was bound in oxygen compounds), but there was a lot of water vapor and substances such as ammonia, cyanogen and others. Undoubtedly, the water of the oceans was also saturated with these substances. Thus, the conditions for the emergence of numerous carbon compounds were gradually created - complex organic substances... The largest number of them arose, of course, in water bodies, for water has always been an active mediator and participant in chemical processes. Academician A.I. Oparin wrote:

The external conditions that were created in the reservoirs of the primordial ocean were not much different from those that we can reproduce in our laboratories. Hence, it is clear that at any point in the ocean of that time, in any lagoon and drying puddle, the same complex organic substances should have formed that were obtained in Butlerov's flask, in a Bach glass and other similar experiments.

Sequentially, step by step, Oparin traces the possible path of development of inanimate matter and its transformation first into the simplest organic substances, consisting of carbon, hydrogen, oxygen and nitrogen, and then into complex proteins and, finally, into living protein bodies... All these chemical transformations took place in an environment natural for the development of our planet. It is difficult to say in what form life originally existed on Earth and how long it took to create conditions for the emergence of life on Earth, so that it took on more highly organized forms. Scientific assumptions based on the study of chemical and physical properties substances based on astronomical data on the processes occurring during

For life to arise, three conditions had to be met. First, groups of molecules capable of self-reproduction had to be formed. Second, copies of these molecular complexes had to have variability, so that some of them could use resources more efficiently and more successfully withstand the action of the environment than others. Third, this variability had to be inherited, allowing some forms to increase numerically as favorable conditions Wednesday. The origin of life did not happen by itself, but was accomplished due to certain external conditions prevailing by that time. The main condition for the emergence of life is associated with the mass and size of our planet. It has been proven that if the mass of a planet is more than 1/20 of the mass of the Sun, intense nuclear reactions begin on it. The next important condition for the emergence of life was the presence of water. The value of water for life is exceptional. This is due to its specific thermal features: huge heat capacity, weak thermal conductivity, expansion during freezing, good properties as a solvent, etc. The third element was carbon, which was present on Earth in the form of graphite and carbides. Hydrocarbons were formed from carbides during their interaction with water. The fourth prerequisite was external energy. Such energy on the earth's surface was available in several forms: the radiant energy of the Sun, in particular ultraviolet light, electrical discharges in the atmosphere and the energy of the atomic decay of natural radioactive substances. When substances like proteins appeared on Earth, a new stage began in

the development of matter - the transition from organic compounds to living things.

Initially, organic matter was in the seas and oceans in the form

solutions. They did not have any structure, any structure. But

when such organic compounds are mixed with each other, from

solutions, special semi-liquid, gelatinous formations were isolated -

coacervates. All proteinaceous substances in solution were concentrated in them.

substances. Although the coacervate droplets were liquid, they had a certain

internal structure. The particles of matter in them were not located

randomly, as in a solution, but with a certain pattern. At

the formation of coacervates, the beginnings of organization arose, however, still very

primitive and unstable. For the droplet itself, this organization had

great importance. Any coacervate droplet was able to capture from

the solution in which certain substances float. They are chemically

attached to the substances of the droplet itself. Thus, it was flowing

the process of creation and growth. But in any drop along with creation

decay also existed. One or another of these processes, depending on

composition and internal structure of the droplet began to prevail. As a result, in some place of the primary ocean mixed

solutions of protein-like substances and coacervate droplets were formed. They

did not swim in clean water, but in a solution of various substances. Droplets

trapped these substances and grew at their expense. Growth rate of individual

droplets were not the same. It depended on the internal structure of each of

them. If decomposition processes predominated in the droplet, then it disintegrated.

The substances that make up it passed into solution and were absorbed by other

droplets. More or less long, only those droplets existed in

which the processes of creation prevailed over the processes of decay. Thus, all randomly occurring forms of organization by themselves

dropped out of the process of further evolution of matter. Each individual droplet could not grow infinitely as one continuous mass - it disintegrated into daughter droplets. But each droplet at the same time was somehow different from the others and, having separated, grew and changed on its own. In the new generation, all poorly organized droplets died, and the most perfect ones participated in further evolution.

matter. So in the process of the emergence of life, natural selection took place.

coacervate droplets. The growth of coacervates gradually accelerated. Moreover, scientific

data confirm that life did not originate in the open ocean, but in the shelf

zone of the sea or in lagoons, where there were the most favorable conditions for

concentration of organic molecules and the formation of complex macromolecular

systems. Ultimately, the improvement of coacervates led to a new form

the existence of matter - to the emergence of the simplest living beings on Earth.

In general, the exceptional diversity of life is carried out in a uniform

biochemical basis: nucleic acids, proteins, carbohydrates, fats and

several more rare compounds such as phosphates. The main chemical elements from which life is built are

carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. Obviously organisms

use for their structure the simplest and most common in

The elements of the universe are due to the very nature of these elements.

For example, the atoms of hydrogen, carbon, oxygen and nitrogen have small

sizes and form stable connections with double and triple bonds,

which boosts them reactivity... And the formation of complex polymers,

without which the emergence and development of life is generally impossible, is associated with

specific chemical characteristics of carbon. Sulfur and phosphorus are present in relatively small amounts, but they

role for life is especially important. Chemical properties these elements give

possibility of forming multiples chemical bonds... Sulfur is part of

proteins, and phosphorus - component nucleic acids.

Biosphere
The totality of all living organisms forms the living shell of the Earth, or the biosphere. It covers upper part the lithosphere (the hard shell of the Earth), the lower part of the atmosphere (gaseous shell) - the troposphere - and the entire hydrosphere (water shell).

The biosphere is the life of all living organisms associated with natural processes. Living organisms are a gigantic force that transforms appearance planets.
Green plants have shaped the modern atmosphere of the planet and maintain the consistency of its composition. Plants connect us with space, using the energy of the Sun in the process of photosynthesis and storing it in the form of chemical energy of organic substances.
Soil is formed from organic residues with the participation of microorganisms. Coal, combustible gases, peat, oil - all this is created by plants and other living organisms.
Factors of inanimate nature and life
For the development of life on our planet, you need:
- Oxygen;
- Water in liquid state;
- Carbon dioxide;
- Sunlight;
- Mineral salts;
- A certain temperature regime.
Living in different climates
Living organisms have adapted to various climatic conditions.

Some bacteria even live in water used to cool nuclear reactors. The adaptation of plants is very diverse. Plants in arid regions have long roots. The leaves of cacti have changed into thorns, and they store water in the stem. Plants of temperate climates shed their leaves for the winter. Marsh plants have large evaporating surfaces.

What is needed to explain the emergence of life from the standpoint of physics and chemistry, what conditions are needed for the emergence of living things from non-living things? Four basic conditions are believed to be required:

- the presence of certain chemicals,

- availability of an energy source,

- absence of gaseous oxygen О 2,

- a long time.

Of the necessary chemicals, water is abundant on Earth, and inorganic compounds are present in rocks, in the gaseous products of volcanic eruptions and in the atmosphere. The necessary energy has always been provided first of all by the Sun, ultraviolet and other types of radiation, then heat from volcanoes, hot lava, geysers and from the radioactive decay of elements of the earth's rocks, lightning.

It is believed that life could have arisen when the Earth's atmosphere did not contain oxygen. The fact is that oxygen, interacting with organic substances, destroys, oxidizes them and deprives them of those properties that would make them useful for prebiological systems. Therefore, if organic molecules on the early Earth reacted with O 2, they would not exist for long, hinder chemical evolution, i.e.

would not form more complex structures. The presence of atmospheric oxygen is one of the reasons for the impossibility of spontaneous generation of life from organic substances in our time. That is, for the emergence of life, not an oxidizing, but a reducing atmosphere is required.

It is known from geological data that the oldest rocks of the earth were formed at a time when its atmosphere did not contain O 2, but at the time of the supposed origin of Life from water vapor, carbon dioxide, ammonia and nitrogen. In the ancient rocks of the Earth, iron is found in the bivalent reduced form Fe 2+, and in younger rocks - in the trivalent Fe 3+, g.u. in oxidized, which led to the formation of H 2, O, CH 4, NH 3, HCN, and then CO, CO 2, creating a reducing atmosphere. The atmospheres of the other, largest planets of the solar system, Jupiter and Saturn, according to modern data, consist mainly of gaseous and metallic hydrogen and helium. At the same time, the Earth could not hold light hydrogen, it was scattered in space, just like the hydrogen that was obtained during the decomposition of ammonia NH 3 under the influence of solar radiation.

Chemical reactions leading to the formation of new substances can proceed with different speeds... Such transformations of the primordial atmosphere of the Earth took millions of years. However, taking into account the estimated time of the formation of the Earth of 4.6 billion years, simple calculations show that even if the probability of an event on which the emergence of at least once the simplest forms of life depended is 0.001, then in 10,000 years it will surely occur. Therefore, no matter how unlikely the appearance of living systems may seem, there was so much time for this that in fact this event became inevitable. For example, the first known remnants of prokaryotic cells were found in rocks that formed only (!) 1.1 billion years later than the formation of the Earth.

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Conditions for the existence of biological life on Earth.

Chapter 3. Earth - the cradle of humanity

According to the American physicist, laureate Nobel Prize in 1979 by Stephen Weinberg, “now the very science that killed God is restoring faith in Him. Physicists stumbled over the signs that the Cosmos is designed specifically for the existence of Life and Consciousness. "

The earth was created in such a way that the conditions existing on it were conducive to human life.

In Russian science, in pursuance of the will of V.I. Vernadsky, a long-term cycle of unique heliometric studies was completed. It was found that observed on Earth life processes flow only in the human habitat - the thinnest boundary layer between the cold Space and the hot, chemically aggressive bowels of the Earth, real ideas about which in modern science until 1991 they were absent. It cannot be an accident that the conditions of this habitat, ideal for biosystems, have been preserved for millions of years. Our planet was formed with deliberate and thoughtfulness. This is confirmed by the numerous facts collected in his book "Melchizedek" by the writer-philosopher Victor Nyukhtilin. Judge for yourself.

For the Earth and its inhabitants, the Sun is a source of light, heat and vital energy. The Earth is not accidentally, but is specially located from the Sun at a distance of about 150 million km. It is at this distance that the ideal supply of the earth with the energy that provides life is carried out. If the Earth were a little closer to the Sun, then it would be like a hot frying pan, and if a little further, it would be covered with a shell of ice.

The Earth revolves around the Sun at a speed of about 107 thousand km per hour. It is this speed that keeps the Earth at the right distance from the Sun.

The Earth's atmosphere, passing solar heat through itself to the Earth, heats up and wraps the Earth in a kind of warm blanket from gases, isolating it from the cold Space. Moreover, due to its special composition, the atmosphere warms the Earth, but does not overheat. It does not create stuffiness that is superfluous, killing all living things.

Oxygen is placed in the Earth's atmosphere. He provides life. However, pure oxygen is a "poison", it is an accelerator of chemical processes that leads all living things to an early death. In addition, oxygen supports combustion, and if there was too much oxygen, the entire Earth would be completely covered with incessant, all-destroying fires. To make the "killer" a vital elixir, nitrogen is added to the oxygen. Oxygen in the atmosphere 21%, nitrogen - 78%. It is in this mixture that oxygen loses its negative qualities and gains the ability to maximize its positive properties …… ..

Plants cannot live without carbon dioxide. They metabolize it and release oxygen. Therefore, this gas is also placed in the atmosphere. People and animals, on the other hand, breathe in oxygen and emit carbon dioxide. An increased content of carbon dioxide would lead to suffocation of people and animals, and a lower content would lead to the death of plants. In an atmosphere of carbon dioxide, 1% is just the amount that is required to satisfy the needs of everyone, and which is optimal for life …….

The ozone layer protects living organisms on Earth from the harmful effects of the short-wave ultraviolet component of the Sun's radiation, which means it also protects Life …….

There is nothing like water on Earth, and one gets the impression that it is a unique Essence, created by the Creator especially for the physical world …….

The uniqueness of water is manifested in the fact that it is the only substance on the planet that occurs naturally in all three states of aggregation (in the form of vapor, liquid and ice).

In fact, water does not obey physical laws, and if it obeyed, life on Earth would become impossible. Indeed, any substance shrinks upon cooling, while water expands. Ice, as you know, floats on its surface, and does not sink to the bottom, as would be expected for a substance in a solid phase. If the ice sank to the bottom, the reservoirs would freeze through their entire depths, and life in them would be destroyed.

The Earth constantly, every 24 hours, revolves around its axis - this is how day and night, light and darkness change. In time, this coincides with the cycle of sleep and wakefulness of living organisms. It coincides, and does not define this cycle. According to the latest studies, the biological organism rests in sleep and is awake after rest according to a clock that works independently, built somewhere inside it.

Scientists have conducted an interesting experiment with volunteers. The people under study were placed at a depth of 400 meters underground, in the Mammoth Cave, located in the state of Kentucky (USA), so that they could not be affected not only by changes in the illumination of the sky, but also by other geophysical phenomena accompanying the changes of day and night. Constant continuous illumination was created for the subjects …….

The results of the experiment led to interesting conclusions. Thus, the Creator divided the day into day and night, so that darkness would be a period of rest that occurs in the body, and daytime would be a period of activity.

The simultaneous onset of the time of rest for all living things is ensured by the onset of twilight. Our internal chronometer is designed in such a way that it perceives the darkening of the palate as the starting point of the body's transition to a state of sleep. A decrease in the illumination level is, as it were, a signal of a general rejection …….

So, the speed of rotation of the Earth around its axis is adjusted so as to ensure the maximum comfort of our general rest and our simultaneous activity, which clearly indicates that everything is made for Life, and not Life has adjusted itself to existing circumstances. The physical world simply serves Life. Regardless of the different duration of daylight in humans and at the equator, and in the area of polar nights, and even at space stations, the cycle of sleep and wakefulness is the same. If we were to adapt to the rotation of the Earth, and not it to us, then different biological cycles would dominate in different parts of the globe. And they are the same everywhere …….

About 10 thousand celestial objects cross the Earth's orbit with their constant visits to the solar system, a collision with each of which can cost us our lives. But for millions of years, nothing like this has ever happened. When mathematicians are fuming and say that, according to any calculations of the theory of probability, this is impossible (that is, various collisions must necessarily occur), then astronomers only shrug their shoulders - and the goblin knows why collisions do not occur. At the same time, they say that in each of the cases of a possible impact (and such situations have arisen repeatedly), some planets deviated from their position and, with their gravitational influences, deflected the trajectory of the killer comets, that is, “knocked them off the sight”, and then returned to their previous positions ... The reasons for this behavior are unknown to science ... ... ..

End of the introductory version of a fragment of the book

Page 1
Cognition of the world 2nd grade I quarter

Test No. 1
Purpose: To reveal the knowledge of students about the properties of water, air, the ability to practically apply knowledge, to establish the simplest connections in living and inanimate nature.

Conditions necessary for human life:

A) water, food, heat

B) air, light, fur coat

C) water, food, air, light, heat.

The space visible around you is:

A) horizon

B) horizon line

C) the surrounding world.

The device for determining the sides of the horizon is:

A) thermometer

B) compass

The plan is:

A) top view of the object

B) the image of the object as you are used to seeing it

C) the space visible around you.

Air properties

A) transparent, elastic, supports combustion

B) elastic, poor heat conductor, supports combustion, odorless, occupies a certain space, transparent

C) white, odorless, occupies a certain place.

6. Water properties

a) liquid, odorless

b) colorless, fluid, odorless

c) has no color, no smell, no definite shape, fluid,

liquid, solvent.

Wildlife is:

a) sun, air, water, clouds, stones, sky

b) plants, animals, humans

c) everything that was done by human hands.

8. The main sides of the horizon

a) North, south, west, east

b) northeast, southwest, southeast, northwest

c) North, south, west, east, north-east, south-west,

southeast, northwest.

* If tourists went on a trip to the north, then in which

direction will they return home?

* Write down proverbs and sayings about labor.
Evaluation criteria:

"5" - 8 tasks without errors

"4" - 1 error

"3" - 2 errors

Cognition of the world 2nd grade II quarter

Test number 2
Purpose: To reveal the knowledge of students about the soil, its properties, the ability to distinguish between plants and apply their knowledge in life.
1. What is soil?

a) loose fertile soil layer;

b) the black layer of the earth on which the plants grow;

c) a loose, fertile layer of earth on which plants grow.

2. The main property of the soil:

a) is black

b) consists of clay, sand and humus

c) fertility.

3. Plant organs are:

a) root, stem, leaves, flowers

b) seeds, fruits, branches, cones.

c) fruit, root, stem, leaves, flowers.

4. What is the name of the substance that gives plants their green color?

a) pigment

b) chlorophyll

c) melanin

5. Indicate the conditions necessary for plant life

a) light, warmth

b) water, light, heat, air, nutrients

c) air, light.

6. The ability of each plant to keep such a generation for itself is:

a) development

b) reproduction

c) maturation

7.Plant groups:

a) trees, shrubs, grasses

b) seeds, tubers, whiskers

c) flowers, herbs, berries

8. The root is:

a) the underground organ of the plant

b) the terrestrial organ of the plant

9. Fruits are:

b) dry, juicy

c) juicy

* What is the name of the cut, dried grass intended for animal feed.
* Learn by description:

Garlands of small bells hang in the spring between large pointed leaves.

And in the summer, a red berry appears in place of flowers, but do not take it in your mouth - it is poisonous. It …….

Evaluation criteria:

"5" - 9 tasks without errors

"4" - 1 error

"3" - 2 errors

Cognition of the world 2nd grade III quarter

Test number 3
Purpose: To reveal knowledge and skills, to briefly characterize the value of the animal world on earth, to distinguish between the concepts of the capital, law, customs.

Predators include:

2... Hibernates:

a) bear

They can live for a long time without water:

a) horse

b) camel

e) frog

4. Herbivores include:

c) horse

5... Insects include:

a) dragonflies

b) caterpillar

d) lizard

6. Lays eggs:

a) reptiles

b) insects

c) amphibians

7. Life goes on because animals have:

a) the ability to eat

b) the ability to reproduce

8. The orderly of the forest:

c) bear

9. The word "constitution" means:

a) device

c) well-being

10. Capital of the Republic of Kazakhstan:

a) Almaty

b) Kostanay

c) Astana

* Who is the cuckoo's cuckoo (male or female)?

* Which animal has cubs in winter?

a) forty

b) starling

c) sparrow

d) nightingale

Evaluation criteria:

"5" - 10 tasks without errors

"4" - 1 error

"3" - 2 errors

Cognition of the world 2nd grade IV quarter

Test number 4
Purpose: To reveal general knowledge about society about the occupations of people.

White bread gives us:

b) wheat

2... White gold is:

c) cotton

3. A large flock of sheep is called:

4. Agricultural professions include:

a) metallurgist

b) miner

c) machine operator

d) agronomist

5. Shrubs grow in the gardens:

a) raspberries

b) lilac

c) currants

d) apple tree

6. Melon crops include:

a) cabbage

d) beans

7. Camel milk drink:

* What is the thinnest thread in nature?

* Does the person breathe through the skin?

* What will happen to a bee after she stings a person?

* Write down the proverb about the book
Evaluation criteria:

"5" - 7 tasks without errors

"4" - 1 error

"3" - 2 errors

Page 1

Ecology Olympiad School Tour Assignments

6th grade

choose correct definition... Ecology is:

a) a science that studies the living conditions of living organisms in their habitat and their relationship with each other;

b) plant science;

c) the science of nature.

What are the most necessary environmental conditions for the life of organisms?

The doctrine of the biosphere was developed by:

I. Vernadsky;

b) C. Darwin;

c) E. Haeckel

Why do plants in deserts have time to bloom and bear fruit in 3-4 weeks?

Vegetation resembling tundra vegetation grows:

a) in the foothill steppes;

b) in coniferous mountain forests;

c) near the snow line.

List the abiotic environmental factors.

Choose plants that are weak on their own.

a) birch;

b) bindweed;

f) grapes.

In the life of what living organisms is light most important for life?

Fragrant tobacco is pollinated by moths.
How do they find it?

In which natural zone do plants store moisture?

What colors of the solar spectrum do plants use in the process of photosynthesis?

Define the following concepts:
- fertility;
- biosphere;
- habitat;
- photosynthesis;
- environmental factors.

How to prove that there is air in the soil?

List the main types of relationships between living organisms.

Make a food chain: eagle, grass, grasshopper, snakes, frog.

Guess the riddle: There is a carpet of green coins on the water.

Take it away - and there is no food!

What is this plant? For whom is it food?

List the main differences between plants and animals and their relationship to the environment.

Review the drawing and determine the effect of light on plant growth.

List the plant groups in relation to daylight hours.

List the plant groups in relation to warmth and cold.

Answers

heat, light, moisture, air, mineral salts, neighboring organisms
this is how long the wet period lasts in deserts
warmth, light, humidity, air
b, d, e, f
in plant life
flowers of fragrant tobacco white, so they are easily visible in the dark
in the deserts
red, blue, purple
fertility is the ability of the soil to produce crops

the biosphere is a special shell of the Earth, inhabited by living organisms
habitat is everything that surrounds a living organism and with which it directly interacts

photosynthesis - aerial nutrition of plants; the process of the formation of organic substances from inorganic in leaf cells in the light

environmental factors are those elements of the environment or weather phenomena that have a direct impact on a living organism.

if you throw the soil into a glass of water, then after a while air bubbles will begin to emerge from the soil
mutually beneficial, useful-neutral, useful-harmful, mutually harmful.
grass - grasshopper - frog - snakes - eagle
duckweed; is food for ducks

differences	plants	Animals
way of eating	Absorb mineral substances from the environment and form organic substances in the process of photosynthesis	They feed on ready-made organic matter
degree of mobility	They take root in the soil and live permanently in one place	Can actively move in space
duration of growth	Grow all my life	Growth is limited, most stop growing when they reach adulthood
the number of organs and the methods of their formation	Have many of the same organs that are constantly being updated	The number of organs is limited and constant, functioning throughout life without replacement
reaction to external influences	Under favorable conditions, they respond with increased growth and education. a large number fruits and seeds. If unfavorable, they fall into a state of forced or deep rest	With poor nutrition, they lose weight, with good nutrition, they get fat and bring more offspring. They can make long transitions in search of food.
ways of protection	Form poisonous and odorous substances, emit volatile substances that kill bacteria, have thorns	They hide and hide, have an adaptive and warning coloration, needles and thorns

if a dandelion grew in shade among dense grass, then its leaves are long, located almost vertically, and the stems with inflorescences are also long. They seem to be drawn to the light (1). Dandelions grown in a well-lit place among a low grass stand in a meadow near a road have shorter stems and leaves (2).
plants are short, long day and neutral.
heat-resistant, moisture-loving, cold-resistant, frost-resistant, ice-resistant

Recently I watched a program about the uniqueness of our planet, which became a favorable "soil" for the emergence of life. In addition, various hypotheses have been made as to whether what forms of life are possible on other planets. The information is very interesting, and therefore I will briefly outline the essence of what I have learned.

Necessary conditions for life

What is life? In fact, it is complex chemical process- interaction and reaction between molecules and atoms. But what is needed to complete this process? In fact, there are only 3 conditions:

a certain set of chemical elements;
energy;
water.

Concerning wildlife in general, it develops in a unique environment where the main living conditions are:

availability of food;
optimal temperature;
water;
air.

The combination of all of the above conditions found only on our planet... Despite the large number of planets studied, none of them has such a uniqueness. Of course, given the theoretical infinity of the universe, it is perfectly acceptable to assume that somewhere there is a planet like the Earth. But science, or rather, its capabilities at the present time, do not allow giving a final answer.

Why did life begin

This became possible due to a number of favorable factors:

availability of water- the key element;
optimal size of the planet- in fact, the ideal attraction for the existence of the atmosphere;
presence of an atmospheric envelope- maintains thermal balance, contains breathing air and protects against radiation;
optimal distance from the star- if the planet were a little closer, it would represent a scorched desert, and otherwise it would be covered with ice.

Other life forms

On our planet carbon - "framework" for organic compounds... But is life possible on a different basis? Science has been trying to answer this question for many years, but no significant results have been obtained. It is theoretically possible, and even found alternative to carbon - silicon... It has similar properties, forming the necessary connections and bonds. But here's the catch - this element is heat-resistant, and therefore water will no longer be that universal solvent. For this, it is more suitable sulphuric acid , because its boiling point is much higher. Similar conditions can be observed on Venus.

In addition to silicon, another suitable element is nitrogen... Not so long ago, a group of scientists discovered that when high pressure nitrogen-based compounds are formed, which significantly exceed their potential for carbon compounds. Similar conditions are observed on Neptune and Uranus.

Everyone at least once in his life thought about Are we alone in the universe or not... According to NASA, the answer to this question, mankind will be able to get in 25 years. That's why you just have to wait.

The history of life and the history of the Earth are inseparable from each other, since it was in the processes of development of our planet as a cosmic body that certain physical and chemical conditions were laid, necessary for the emergence and development of life.

First of all, it should be noted that life (at least in the form in which it functions on Earth) can exist in a fairly narrow range of temperatures, pressures and radiation. Also, for the emergence of life on Earth, quite certain material bases are needed - chemical elements-organogens and, first of all, carbon, since it is this that underlies life. This element has a number of properties that make it indispensable for the formation of living systems. Carbon is capable of forming a variety of organic compounds, the number of which reaches several tens of millions. Among them are water-saturated, mobile, low-conductivity structures twisted in a chain. Compounds of carbon with hydrogen, oxygen, nitrogen, phosphorus, sulfur and iron have good catalytic, construction, energy, informational and other properties.

Along with carbon, oxygen, hydrogen and nitrogen are among the “building blocks” of living things. After all, a living cell consists of 70% oxygen, carbon in it - 17%, hydrogen - 10%, nitrogen - 3%. Organogenic elements belong to the most stable and widespread chemical elements in the Universe. They easily combine with each other, enter into reactions and have a low atomic weight. Their compounds dissolve easily in water. These elements, apparently, came to Earth along with cosmic dust, which became the material for the "construction" of the planets of the solar system. Even at the stage of planetary formation, hydrocarbons, nitrogen compounds arose, in the primary atmospheres of the planets there was a lot of methane, ammonia, water vapor and hydrogen. They, in turn, have become raw materials for the production of complex organic substances that make up proteins and nucleic acids (amino acids and nucleotides).

Water plays a huge role in the appearance and functioning of living organisms, because they are 90% water. Therefore, water is not only a medium, but also an obligatory participant in all biochemical processes. Water supports cell metabolism and

thermoregulation of organisms. In addition, the aquatic environment, as a structure unique in its elastic properties, allows all molecules that determine life to realize their spatial organization. Therefore, life originated in water, but even come out of the sea onto land, it has preserved the oceanic environment inside a living cell.

Our planet is rich in water and is located at such a distance from the Sun that the bulk of water necessary for life is in a liquid, and not in a solid or gaseous state, as on other planets. Earth is at the optimum temperature for carbon-based life.

What was the oldest life like?

Our knowledge of previously living organisms is limited. After all, billions of individuals representing the most different types, disappeared without leaving any traces behind. According to some paleontologists, only 0.01% of all species of living organisms that inhabited the Earth have survived in the fossil state. Among them are only those organisms that could preserve the structure of their forms by replacement or as a result of the preservation of prints. All other species simply did not reach us, and we will never be able to learn anything about them.

For a long time it was believed that the age of the oldest imprints of living organisms, which include trilobites and other highly organized aquatic organisms, is 570 million years. Later, traces of much more ancient organisms were found - mineralized filamentous and rounded microorganisms of about a dozen different species, resembling the simplest bacteria and microalgae. The age of these remains, found in the siliceous strata of Western Australia, was estimated at 3.2-3.5 billion years. These organisms, apparently, had a complex internal structure, they contained chemical elements, the compounds of which were able to participate in the process of photosynthesis. These organisms are infinitely complex in comparison with the most complex known organic compound of abiogenic origin. There is no doubt that these are not the earliest life forms and that there were more ancient predecessors.

Thus, the origins of life on Earth go back to that "dark" first billion years of our planet's existence, which left no trace in its geological annals. This point of view is also confirmed by the fact that the well-known biogeochemical carbon cycle associated with photosynthesis stabilized in the biosphere more than 3.8 billion years ago. This allows us to consider that the photoauto-trophic biosphere existed on our planet at least 4 billion years ago.

years ago. However, according to the data of cytology and molecular biology, photoautotrophic organisms were secondary in the process of the evolution of living matter. The autotrophic method of feeding living organisms should have been preceded by the heterotrophic method as a simpler one. Autotrophic organisms, which build their bodies at the expense of inorganic minerals, have a later origin. This is evidenced by the following facts:

All modern organisms have systems adapted to the use of ready-made organic substances as a source building material for biosynthesis processes;

The predominant number of species of organisms in the modern biosphere of the Earth can exist only with a constant supply of ready-made organic substances;

In heterotrophic organisms, there are no signs or rudimentary residues of those specific enzyme complexes and biochemical reactions that are characteristic of the autotrophic mode of nutrition.

Thus, we can conclude that the heterotrophic feeding method is primary. The earliest life probably existed as heterotrophic bacteria that received food and energy from organic material of abiogenic origin, which was formed even earlier, at the cosmic stage of the Earth's evolution. Consequently, the beginning of life as such is postponed even further, beyond the stony record of the earth's crust, more than 4 billion years ago.

Speaking about the oldest organisms on Earth, it should also be noted that by the type of their structure they were prokaryotes, which arose shortly after the appearance of the arcellular. Unlike eukaryotes, they did not have a formed nucleus, and DNA was located in the cell freely, without being separated from the cytoplasm by the nuclear membrane. The differences between prokaryotes and eukaryotes are much deeper than between higher plants and higher animals: they both belong to eukaryotes. Representatives of prokaryotes live today. These are bacteria and blue-green algae. Obviously, the first organisms that lived in the very harsh conditions of the original Earth were similar to them.

Scientists also have no doubt that the most ancient organisms that inhabited the Earth were anaerobes that received the energy they needed through yeast fermentation. Most modern organisms are aerobic and use oxygen respiration (oxidative processes) as a way to obtain energy.

Thus, V.I. Vernadsky was right when he suggested that life immediately arose in the form of a primitive biosphere. Only

a variety of species of living organisms could ensure the performance of all functions of living matter in the biosphere. After all, life is a powerful geological force, quite comparable in both energy costs and external effects with geological processes such as mountain building, volcanic eruptions, earthquakes, etc. Life not only exists in its environment, but actively forms this environment, transforming it “for itself”. It should not be forgotten that the entire face of the modern Earth, all its landscapes, sedimentary and metamorphic rocks (granites, gneisses formed from sedimentary rocks), mineral resources, the modern atmosphere are the result of the action of living matter.

These data allowed Vernadsky to assert that from the very beginning of the existence of the biosphere, the life included in it should have already been a complex body, and not a homogeneous substance, since the biogeochemical functions of life, due to their diversity and complexity, cannot be associated only with any one form life. Thus, the primary biosphere was originally represented by a rich functional diversity. Since organisms are manifested not singularly, but in a mass effect, the first appearance of life should have occurred not in the form of any one kind of organisms, but in their totality. In other words, primary biocenoses should have appeared immediately. They consisted of the simplest unicellular organisms, since without exception all the functions of living matter in the biosphere can be performed by them.

And finally, it should be said that primary organisms and the biosphere could only exist in water. We have already said above that all organisms on our planet are intimately connected with water. Exactly bound water, which does not lose its basic properties, is their most important component and accounts for 60-99.7% of the weight.

It was in the waters of the primary ocean that the “primary soup” was formed. After all sea water itself is a natural solution containing all known chemical elements. In it, at first simple, and then complex organic compounds were formed, among which were amino acids and nucleotides. It was in this “primordial soup” that the leap took place, which gave rise to life on Earth. Of no small importance for the emergence and further development of life was the radioactivity of water, which was then 20-30 times greater than now. Although primary organisms were much more resistant to radiation than modern organisms, mutations were much more frequent in those days, so natural selection was more intense than today.

In addition, one should not forget that the primary atmosphere of the Earth did not contain free oxygen, therefore there was no ozone screen in it, which protects our planet from ultraviolet radiation from the Sun and hard cosmic radiation. For these reasons, life on land simply could not arise, life arose in the primary ocean, the waters of which served as a sufficient obstacle for these rays.

So, summing up, it should be noted that the primary organisms that arose on Earth more than 4 billion years ago had the following properties:

They were heterotrophic organisms, i.e. fed on ready-made organic compounds accumulated at the stage of the Earth's cosmic evolution;

They were prokaryotes — organisms lacking a shaped nucleus;

They were anaerobic organisms using yeast fermentation as an energy source;

They appeared in the form of a primary biosphere, consisting of biocenoses, including different kinds unicellular organisms;

They appeared and existed for a long time only in the waters of the primary ocean.

The beginning of life on Earth

Since life is inextricably linked with its environment, the beginning of life should be studied in close connection with those cosmic and geological processes during which our planet was formed and developed.

The completion of the stage of the Earth's cosmic evolution, during which it was formed from planetesimals, took place about 4.5 billion years ago. After that, our planet began to gradually cool down and the earth's crust began to form, as well as the atmosphere and hydrosphere due to degassing of lavas melted from the upper mantle during intense volcanism. We have every reason to believe that, at the same time, water vapor and gaseous compounds of carbon, sulfur and nitrogen entered the Earth's surface.

Primary atmosphere The earth was very thin, rarefied, the atmospheric pressure at the surface did not exceed 10 mm Hg. The composition of the primary atmosphere was formed from those gases that were emitted during volcanic eruptions. This is confirmed by the analysis of gas bubbles found in the proto-Archean rocks (60% - carbon dioxide, 40% - compounds of sulfur, ammonia, methane, other carbon oxides, as well as water vapor). Primary atmosphere

Primary ocean waters had about the same composition as today, but they, like the atmosphere, lacked free oxygen. Thus, free oxygen, and therefore chemical composition the modern atmosphere, like the free oxygen of the Earth's oceans, was not originally set at the birth of our planet as celestial body, but are the result of the vital activity of the first living organisms that made up the primary biosphere of the Earth.

Under the influence of solar and cosmic rays, penetrating through the rarefied atmosphere, its ionization took place, transforming the atmosphere into cold plasma. Therefore, the atmosphere of the early Earth was saturated with electricity, frequent discharges flashed in it. Under such conditions, there was a rapid simultaneous synthesis of various organic compounds, including very complex ones. These compounds, like those that came to Earth in a ready-made form from space, were a suitable raw material from which amino acids and nucleotides could be formed at the next stage of evolution.

The radioactive heating of the Earth's interior awakened tectonic activity, volcanoes began to work, emitting a huge amount of volcanic gases. This condensed the atmosphere, pushing the ionization boundary to its upper layers. In this case, the process of the formation of organic compounds continued.